Cobb Theatres is working with the sheriff’s office on the investigation, the Birmingham, Ala., company said in a written statement.

“This was an isolated altercation between two guests that escalated unexpectedly,” the statement said. “The safety, security and comfort of our guests and team members are always our top priorities, and we are truly heartbroken by this incident.”

The incident rouses concerns about safety and security in public spaces, especially movie theaters.